JPS60125386A - Filter press type electrolytic cell - Google Patents

Abstract

PURPOSE:To provide the titled electrolytic cell which improves electrolytic efficiency with simple and inexpensive construction by forming flow regulating regions which disperse uniformly the flow of the electrolyte introduced into the cell over the entire region of electrodes to chamber frames which are disposed adjacently to electrolyte supporting frames and form electrolytic chambers. CONSTITUTION:A filter press type electrolytic cell is constituted by combining chamber frames 2, 3, 12, 13 which have electrodes 1a, b, introducing ports 8, 23 for an electrolyte and leading-out ports 9, 24 and are disposed adjacently to said electrodes 1a, b to form electrolytic chambers as well as diaphragms 14, 15, 16, 17, etc. Electrode holding frames 10a, b which are fitted with the electrodes 1a, b and hold said electrodes are provided in apertures 101a, b having the same thickness and shape as the thickness and shape of the electrodes 1a, b of the above-mentioned electrolytic cell. At least either one of the ports 8- and ports 9 of said frames 2- disposed adjacently to said frames is positioned outer than the end edges facing the electrodes 1a, b. The flow regulating regions which disperse the flow of the electrolyte along the above-mentioned end edges are thus formed, by which the flow rate of the electrolyte is distributed approximately uniformly over the entire region of the electrodes 1a, b and the high current efficiency is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filter press type turtle stack having an electrode and a chamber frame having an inlet and an outlet for an electrolytic solution and arranged adjacent to the electrode to form an electrolytic chamber.

A filter press consisting of electrodes, chamber frames, and, if necessary, diaphragms stacked parallel to each other and alternately! [Layer stacking is well known in the art, and a portion of such an electrolytic cell is shown in FIG.

In the figure, (1) is an electrode, for example an anode, (21, +3
Reference numeral 1 denotes a chamber frame disposed adjacent to both sides of the electrode (1), and each includes an anolyte supply port (41), an anolyte discharge port (5), a catholyte supply port (6), Catholyte drain port (
7). The chamber frames (21 and 31 each have an anolyte inlet (8) and an anolyte outlet (9), and the anolyte introduced from the anolyte inlet (81) comes into contact with the surface of the electrode (11). Electrolysis occurs and the anolyte is discharged through the anolyte outlet port +91 to the anolyte discharge port (51). A filter press type electrolytic cell is constructed by stacking them alternately.

Incidentally, such a filter press type electrolytic cell is required to have a low sliding voltage, the ability for generated gas to escape from the electrolytic chamber quickly, and high current efficiency. In order to increase the current efficiency, it is necessary to distribute the electrolytic solution as evenly as possible along the electrode so that the rate of mass transfer of the electrolyte to the electrode surface becomes uniform over the entire electrode area. To this end, conventional methods include inserting liquid distribution plates, spacers, turbulence promoters, etc. into the electrolytic chamber, and processing the electrode surfaces with irregularities. However, although these methods are suitable for large-scale production such as salt electrolysis, they are not suitable for relatively small-scale production, such as organic electrolysis, because the equipment is complicated and the manufacturing cost is high. However, even if these measures are taken, the room frames f21 and +31 as shown in Figure 1 are not necessarily suitable.
The mass transfer rate is high near the electrolyte inlet (8) and outlet (9), where the flow rate of the electrolyte is high, and low in the middle; ), there is also large variation in the distribution of mass transfer velocity in the lateral direction.

The present invention has been made in order to eliminate such drawbacks of the conventional ones, and it is possible to distribute the electrolyte flow rate almost uniformly over the entire electrode area with an extremely simple and inexpensive structure. The purpose is to provide a type electrolytic cell.

An embodiment of the present invention will be described below with reference to FIG. In Figure 2, (21 to (91) are the same as those in Figure 1, so their explanation will be omitted. (1a) is the anode, (1b)
is a cathode, and according to the invention, each electrode (la), (lb
) are provided with electrode holding frames (10a) and (10b) that fit and hold the electrodes.

Each electrode holding frame (10g), (10b) has a corresponding electrode (
Same thickness and same shape (same size) as la) and (lb)
It has openings (101m>, (101b).(l
la) and (llb) are power supply terminals for each electrode (Ilm) and (lb), and (12) and (13) are chamber frames arranged on both sides of the cathode (1b).

Anode (1a), its holding frame (10a) and chamber frame (2+
, (The assembled state of 31 is shown in Fig. 3,
As clearly shown in Fig. 3, the anolyte inlet (8) (more precisely, its outlet (81)) and the anode 1rl outlet (
91 (more precisely, its inlet (91)) is located outward from the corresponding edges (12a), (13'a) of the anode (1a), and is connected to the anolyte inlet 1B+ and the anode (1a). )
The corresponding edge of (12M),! : A rectifying region (14) is formed between which the introduced electrolyte (in this case the anolyte) is dispersed along the edge (12a), and likewise the anolyte outlet (9) and the anolyte outlet (9).

A similar rectifying region (15) is formed between the anode (1a) and the corresponding edge (13a). The rectifier region (15) is for maintaining the electrolyte to be discharged still substantially uniformly distributed along the edge (135k) when passing through the edge (13a). In this way, the electrode edge (12a)
.

(13a), the electrolyte is dispersed and flows at a uniform flow rate, so that the flow rate of the electrolyte becomes uniform over the entire area of the electrode (1 m) in the width direction and height direction of the electrode (1a), and therefore the electrode The rate of mass transfer to the electrode (1a) is made uniform over the entire area, and the current efficiency is improved. The cathode (lb), its holding frame (10b), and the chamber frames (12) and (13) on both sides thereof are assembled in exactly the same manner as the anode (1g) described above to form a rectifying region.

Both the electrode holding frame and the chamber frame have simple shapes, and can be easily made, for example, by cutting, punching, or punching a resin sheet.

In addition, in FIG. 2, (14) and (15).

(16) and (17) are diaphragms such as ion exchange membranes, and (18), (19), (20), and (21) are diaphragms (14), (15), and (16), respectively.

(17) is a spacer that maintains the distance between the electrodes (la) and (lb), and (22) is the electrode (18).

(1b) Press and hold the chamber frame (2) with an electrode support rod.

+31, (12), (13) have the same thickness, and for ease of assembly spacers (1B), (1
9).

(20) and (21) are joined. (23) is the room frame (
12) and (13), and the catholyte supply port (6)
The catholyte inlet (24) is in communication with the catholyte inlet, and the catholyte outlet (24) is in communication with the catholyte outlet (7). In this embodiment, the electrolytic solution inlet (8).

(23) and the outlet ports 19+ and (24) are all grooves carved on the side of the chamber frame opposite to the side that contacts the diaphragm at an angle that disperses the electrolyte within the chamber frame. It is formed as. The fan-shaped portion in which such a groove is formed can be formed separately and detachably attached to the chamber frame body. 12), (13), diaphragm (14)
, (15).

A sealing member such as a gasket may be placed between (16), (17), etc. to seal the space between them. Power supply terminals (l1M), (llb) of electrodes (la), (lb)
) and the corresponding electrode holding frames (10M) and (10b) can also be sealed with packing, grease, or the like. Generally, an electrolytic cell is formed by stacking a large number of the structures shown in FIG.

Another embodiment of the invention is shown in FIG.

In this embodiment, the electrode holding frame (10a) is used in the embodiment shown in FIG.
The chamber frame (21, +31) are separate pieces, but the chamber frame (21) is attached to the electrode holding frame (10a) with adhesive or fused to package it. Needless to say, a configuration similar to this can also be adopted for the electrode holding frame (10b) and the chamber frame (12) or (13).

Yet another embodiment of the invention is shown in Figure @5. This embodiment takes the packaging shown in FIG. 4 one step further. That is, in this embodiment, both the electrode holding frames (chamber frames +21 and 131) are fixed.In order to make the electrode (1a) detachable, the opening of one chamber frame (3) is fixed. 31) is shaped and sized to allow the electrode (1a) to pass in the direction perpendicular to its surface, that is, in the direction of the arrow (25), and the portion (32) of this opening (31) from which the power supply terminal (lla) protrudes is The closure piece (33) is designed to close with a closure piece (33).The closure piece (33) and the portion (32) closed by it have a shape that locks with each other as shown in the figure to prevent the closure piece (33) from falling off. The locking part (33
1).

(332): It is preferable to provide (321) and (322).

In the above embodiment, the rectifying zone is provided on both the electrolyte inlet side and the electrolyte outlet side of the electrode, but a considerable effect can be obtained even if it is provided on either side. Further, at the end of the electrolytic cell, a chamber frame is generally provided only on one side (inner side) of the electrode, or the present invention can also be applied there as well. Furthermore, although the above embodiments have described a monopolar filter press type diaphragm electrolytic cell, the present invention can be easily applied to a bipolar filter press type diaphragm electrolytic cell and a non-diaphragm type filter press type electrolytic cell. . For example, to form a bipolar filter press type electrode layer stack, in FIG. 2, the chamber frames (31, (12) are rotated 180 degrees vertically and placed,
, (10b) opening (101a).

It is best to stick a rubber sheet seal or the like to the inner edge of the electrode (101b), and hold the outer edges of the electrodes (la) and (lb) in a sealed manner with a comb sheet packing. In this case, no power supply terminals are required except for the electrodes at both ends of the electrolytic cell, and no power supply terminal protrusion is required on the electrode holding frame, and it would be better if the electrodes had a simple square opening. Become.

Electrode holding frame (-10M), (10b), chamber frame (2).

For T3+, (12), and (13), electrically insulating materials such as hard vinyl chloride, polypropylene, polyethylene, fluorine-containing resin, natural rubber, synthetic rubber, etc. that are corrosion resistant to the electrolyte can be used. can. As the electrode, one suitable for the reaction yarn can be selected from titanium substrate coated with platinum, carbon, graphite, stainless steel, lead, nickel, etc. In addition, when using a spacer, it is preferable to select a spacer that is effective as a so-called turbulence promoter that imparts turbulence to the electrolytic solution, such as a reticulated plastic used in an electrodialysis tank or the like.

As described above, according to the present invention, a rectifying region for the electrolyte is provided on at least one of the electrolyte inlet side and the electrolyte outlet side of the electrode, and the edge of the electrode facing the rectifier region is provided. Since the electrolyte is uniformly dispersed along the electrode, the flow rate of the electrolyte is almost uniform over the entire area of the electrode, and therefore the speed of mass transfer to the electrode surface is also almost uniform over the entire electrode, improving current efficiency. Effects can be obtained. A further important effect is that in the present invention, the electrode holding frame and the chamber frame are formed separately and assembled, so the structure is extremely simple and it can be easily manufactured by cutting resin sheets or the like individually. The advantage is that the above-mentioned improvement in current efficiency can be achieved very easily by using a simple and easily manufacturable frame structure.

The results of a prototype experiment of a filter press type electrolytic cell according to the present invention are shown below as a reference example.

(Reference Example 1) In this reference example, oxalic acid was electrolytically reduced to glyoxylic acid.

Because it was used, the effective electrode area on one side was 10 (7) × 50 images = 5 blood 2 × both sides), and the width was 12 cm and the height was 50 cm as an anode.
Two sheets of graphite with a thickness of 5 mm (the effective area on one side is 10 crn x 50 tM = 5 M x 2 sheets for the same reason as the cathode) were used. In addition, the cathode holding frame (thickness 31n) and the anode holding frame (thickness 5n)
Both cod and chamber frame (thickness 3W+) have external dimensions of 163 cm.
, a hard vinyl chloride plate with a height of 78 crn, a mesh plastic as a spacer (manufactured by Tokyo Special Wire Net Co., Ltd., product number Z-13), a cation exchange membrane as a diaphragm (product name Selemion CMV, manufactured by Asahi Glass Co., Ltd.), adjacent to the diaphragm. A monopolar filter press type diaphragm electrolytic cell as shown in FIG. 2 was assembled using a 1 fl thick soft vinyl chloride plate as a gasket between the chamber frame and the chamber frame.

The upper and lower edges of each electrode were separated by 7.5 spaces from the electrolyte inlet and outlet of the chamber frame, respectively. A steel plate is applied from both ends through a 10 m thick end plate made of hard vinyl chloride.
Tightened with 0 bolts.

A 0.97 M L oxalic acid aqueous solution was used as the catholyte, and 4N hydrochloric acid was used as the anolyte. 51 of each were charged into a glass circulation tank, and both solutions were forced to circulate independently in the electrolytic cell using a pump, using a batch method. Constant voltage electrolysis was performed. The operating conditions are: liquid circulation flow rate 7001/hr (each base edge velocity 25 sub/sec);
Liquid temperature 20℃, starting current 100A (current density 10A/l
), the voltage was 3.7V.

In the electrolytic reaction from oxalic acid to glyoxylic acid, the theoretical amount of electricity was applied, the glyoxylic acid concentration was 082M (quantified value by liquid chromatography), and the current efficiency was 84%. During this time, the current changed from 100 A to 73 A, and the voltage changed from 3.7 V to 4.4 V.

(Reference example 2) In this reference example, copper ions were electrodeposited.

Stainless steel (SUS 304 thickness 3) as the cathode,
An electrolytic cell without a diaphragm was assembled using graphite (5 mm thick) as an anode. The shapes and dimensions of the cathode, anode, electrode holding frame, and chamber frame are the same as in Reference Example 1. The same spacer as in Reference Example 1 was also used.

The electrolytic solution used was one in which copper sulfate was dissolved in a 1.5 W/V% sulfuric acid aqueous solution with a copper concentration of 6 f/l (60001F) R: Naruyou IC. This electrolytic solution 51 was charged into a glass circulation tank, and while forcedly circulating inside the tank at 720 J/hour (linear velocity 50 crn/sec), the electrolytic solution 51 was heated at a temperature of 40° C. and an electric i 2 O.
A (ta density Jlf 4 A/da"), constant current electrolysis was carried out in a batch method.

A current efficiency of 96.7% was obtained by applying the theoretical amount of electricity. The voltage during this time changed from 2.5v to 2.9v. When electrolysis was continued and 1.5 times the amount of skin electricity was applied,
The copper ion concentration in the electrolyte was reduced to IFFm.

After electrolysis is complete, the copper deposited on the cathode is fractionated and peeled off.
The weight was measured to examine the electrodeposition distribution. This result is the 6th
As shown in the figure. As shown in FIG. 6, copper was uniformly electrodeposited on the cathode plate within a measurement error.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a part of a conventional filter press type electrolytic cell, Fig. 2 is an exploded perspective view of an embodiment of the present invention, and Fig. 3 is an assembled state of a part of the embodiment of Fig. 2. In the figures, (A1 is a front view, (A) is a right side view of (A), FIG. 4 is a perspective view showing another embodiment of the present invention, and FIG. 5 is a perspective view of still another embodiment of the present invention. The perspective view and FIG. 6 are diagrams showing the results of electrodepositing copper ions using the electrolytic cell according to the present invention, and the same reference numerals in the figures indicate the same or corresponding parts.
1m), (lb) is the electrode, (10M). (10b) is an electrode holding frame, +21. +31. (12). (13 is the chamber frame, +81, (23) is the electrolyte inlet, +91, (24) is the electrolyte outlet, (14), (
15 is a rectification area. Patent applicant: Tanabe Keisou Co., Ltd. Figure 3 (a) cO) Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1. A filter press type electrolytic cell having an electrode and a chamber frame having an electrolyte inlet and an electrolyte outlet and arranged adjacent to the electrode to form an electrolytic chamber, which is the same as the electrode. An electrode holding frame having an opening having the same thickness and shape in the center and fitting and holding the electrode into the opening is provided, and the chamber frame is arranged adjacent to the electrode holding frame, and an inlet of the chamber frame is provided. and at least one of the outlet ports is positioned outwardly from the corresponding edge of the electrode to form a rectifying region therebetween for dispersing the flow of the electrolyte along the edge. A filter press type electrolytic cell characterized by: 2. The inlet and outlet of the chamber frame are positioned outward from the corresponding edges of the electrode, and the respective edges are located between the inlet and outlet and the corresponding edges of the electrode. 2. The filter press type electrolytic cell according to claim 1, wherein a rectifying region is formed to disperse the flow of the electrolytic solution along the flow direction. 3. Claim 1 in which the chamber frame is fixed to the electrode holding frame
Filter press type electrolytic cell as described in section. 4. In the case where the electrode has a power supply terminal protruding to the outside of the electrode holding frame, the chamber frames disposed on both sides of the electrode holding frame are both fixed to the electrode holding frame, and the An opening having a shape and size that allows the electrode to pass through in a direction perpendicular to the surface thereof is formed, and a portion of the opening corresponding to the power supply terminal is closed with a closing piece. filter press type electrolyzer. 5. The filter press type electrolytic cell according to claim 4, wherein the closing piece and the portion of one of the chamber frames that engage with the closing piece are provided with locking portions shaped to lock each other.